Processing facilities are often managed using process control systems. Example processing facilities include manufacturing plants, chemical plants, crude oil refineries, and ore processing plants. Among other operations, process control systems typically manage the use of motors, valves, and other industrial equipment in the processing facilities.
Valves (whether control valves, rotary valves, or other types of valves) are often critical plant control elements, and they are one of the most common sources of disruptions during plant operations. Valve failures are often difficult to detect or predict because a large number of facilities do not have intelligent valve positioners. Instead, these facilities often use simple current-to-pressure converters (with or without external position sensors) or normal 4-20 mA based valve positioners (which are basically current-to-pressure converters and position sensors in one package).